Filling grate for looms



March 23, 1954 R. M. INGHAM, JR 2,672,895

^ FILLING GRATE FOR LOOMS Filed Sept. 14, 1955 INVENTOR.

ROBERT M. INGHAM,JR.-

BY WML Ww/ ATTORNEY Patented Mar. 215, 1954 Robert" M. Ingham, Jr., S

partanburg, S. C., as-

y signor to Deering Milliken Research Trust, near Pendleton, Oconee County, S. C., a nonprofit trust of Maine Application September 14, 1953,v Serial 379,792

ydevice of the type vhaving a pivoted fork which is adapted to be displaced by the filling yarn i, being pressed against a stationary grate on beatupv strokesy of the lay and adapted to indicate the `.absence of a fillingk yarn on the failure Hof the filling fork being displaced whch,in turn, effects Athe operation of usual devices for stopping the loom or effecting'a bobbin transfer. The present "invention is more particularly concerned with the ,construction of the grate against which the ll- 'ing yarn is pressed by the pivoted fork.

` t As is well known to those skilledin the art,

after continued operation of a loom a consider- "able amount of lint collects in the openings of the grate constituting a part of the filling dervtecting device. In normal operation, if the filling yarn has become broken or is not present for other reasons, the prongs of the lling detecting fork will enter the openings of the grate and thus will not bedisplaced in the usual manner so that the operation of the loom isautomatically stopped If, however, sufficient lint has collected in the openings of the grate, the tines vof the forkwill be displaced as a result of their inability to enter the openings as intended thus giving a false test for the presence of a filling yarn.` The loom will then continue to operate in an improper manner until the absence of filling in the cloth is detected by the loom operator. As it is rcustomary for the loom yoperator to tend a large number of looms, it may bea considerable length of time before the absence of a filling is noticed and this results in considerable delay since the warp and woven cloth must `be pulled back to the proper position.

' AAs the problem of lint collecting on filling detector grates has been present ever` since the advent of the automaticy loom, numerous attempts have in the past been made to design grates that would not collect lint; to design automatic apparatus which would remove the lint collected on the grate before it reached such an accumulation as to cause trouble; or to devise filling detecting apparatus which would not give false readings even in the presence of a substantial accumulation of lint. That these efforts have been, to a large extent, unsuccessfulis evil dent'from the'fact that in mosttextile mills today a'number of employees have the sole duty of progressing from loom to loom and manually brushing the accumulation of lint from the filling detector grates. It is an object of the present invention to eliminate thenecessity for manually brushing the-accumulation of lint from filling detector grates by providing a grate on which lint does not accumulate. 'l They above as well as other objects are ac'- complishedhby an improved grate with exterior surfaces composed of a polymeric material se*- lected from the group consisting of polytetraiiuoroethylene and polytrifluorochloroethyl'ene. It has been surprisingly found that for unknown reasons lint does not'adhere to grate surfaces composedof these materials with suicientte- "nacity that it cannot be removed by the routine air-hosing operations performed in the mill. Looms equipped with lling detector grates having external surfaces of polytetrafluoroethylene or polytrifluorochloroethylene can be operated for weeks or even longer without the necessity of brushing the lint from the openings in the vgrate whereas with the grates now commonly employed, it is necessary to stop the loom revery few hours in order that the accumulation of lint on the filling detector grate can be manually removed.

The exact reasons for the success of the new apparatus of this invention is not fully understood for the simple reason that it has never vbeen fully known why lint adhered to the usual smooth surface metal grate with such tenacity that it was necessary to manually remove the same by brushing. One theory has been that the usual metal grates in the high humidity of the ordinary weaving room collected sufficient moisture to result in the lint becoming rigidly affixed to the metal. This theory has, however, apparently been somewhat disproved by tests in which grates coated with silicone resins were substituted for the ordinary grates having a smooth metal surface. As is well known, silicone resins do not ordinarily collect a surface layer of moisture,

vand. if the above theorywere correct, there should be no lint collected by silicone coated grates. It was found, however, that grates coated with silicone resins' wereno'improvement'over Ygrat'es Withapolished metal surface. Another theory has been that the metal surface of the grate during operation of the loom becomes coated' with a nonconducting coat of size and that static electrical forces then operate to result in the collection of lint. This would apparently, however, not explain why lint should adhere firmly to grates with external surfaces of a silicone resin but not to grates with external surfaces composed of a polymeric material from the group consisting of polytetrafluoroethylene and polytrifluorochloroethylene.

According to .this invention .the grate for the filling device canzbezmolded entirelyof polytetrafluoroethylene or polytriuorochloroethylene or the grates can be predominantly formed from a more rigid material, such as steel, and have only an external coating of polymeric material. It apparently, is only important 4that all external surfaces be composed of either ,polytetrafluoroethylene or polytrifluorochloroethylene.

Polytetrauoroethylene and polytriuorochloroethylene are commercially `available in the form of molding powders which can be;` molded by any one of several techniques. If the improved I.grates of ,thisinvention areto be formedentirely of polymeric material, they can be producedin Vquantity at. arelativelyflow. per unitcost byin- `jection molding. On the other hand, grates having .a metalcore. areusually more desirable from thestandpoint of .rigidity and, since aqueous emulsions of.polytetrauoroethylene and polytriluorochloroethylene, suitable for coatingmetal, are also commercially available, one can simply coat Ythe usual metal lling detector grate-with .polymeric-material with ,satisfactory results. The actual technique of coating `comprises simply spraying, brushing,.or the like, .the emulsion on .the grate. andthen heating to fuse thepolymeric .material .A temperaturerof about .750 F. vap- .pliediora periodof to 20 minutesis usually preferred for coating with polytetrauoroethylene, Vbut .lower temperatures, for instance,'.460-

480 F. appliedior a period of 3,0 minutesto an hour, .generally give A.better results withI polytri- .-.uorochloroethylene A single coat generally gives alrn thickness of approximately .001.inch 4and this.is:sufcient although additional coats canbe applied if desired.

`@ne-embodiment of the invention will now..be described yin greater 1 detail with f reference vto `the accompanying drawing in which: y

-Figure l is .artopplan view of a smallportion of a loom showing the filling detecting device.

.Figure .2 -is a fragmentary elevation looking :substantially ,along line =-22 .in vFigure l1 .and .-showingthe grate and lling. detector fork. in the jrelative position assumed'when'the lay isin beat- -.up position.

Figure 3V is `aviragmentary elevation of `the-iillzingdet-ector fork `substantially along lineA3-3fin .Figure-1.

.Figure -4 is.a view in4 perspectiveof .the grate.

Referringmore specifically to the drawings, f-.therexisI il'lustratedza` loom'irame Y I (I-jon which-f the ibase II `oftheiilling detecting deviceissecured. 'iMounted' onlthebase I I,' in a conventionalfmanfner,'is allng fork slide I2-freeto movelongi- A-Itu`dinally. "The 'i'illing fork slide hasan'extenision, not shown, whichis operativelyconnected with conventional means "for stopping `the loom.

The'loom is also provided with a conventional lay I3 which moves back and forth with respect '.tothebase ISI.

Theloom is also equippedwith 5 a conventional reed I4 and conventional shuttle box I5, only partially illustrated.

The lling fork slide is provided with a longitudinally extending slot I6 and moving within the slot is a conventional goose neck I'I actuated by well known means, not shown.

The lay I3 is provided with the usual well or groove I8 in which grate I9 is partially positioned. The grate I9 is conventional in appearance and is provided with bars 20, 2 I, 22 and 23 which form openings 24, 25 and 26. The bar 20 is provided withan extension 21 whichin .turnisprovided `with an/aperture 28 or .attaching Ithegrate to some portion of the lay such as the shuttle box I5.

IPivotally mounted in the end of the iilling lforkfslidef1`2 is a filling detector fork 29 so po- .,sitioned Ato 4.cooperate with grate I9 in detecting thepresence of..a lling yarn 30 extending across the .frontfaeesuoffthe bars 20, 2|, 22 and 23 on alternate gpicks. .The filling detector fork 29 is provided with tines 3 I, 32 and 33 adapted to enter openings 24,25and 26 in grate I9 unless preventedfrom doing so by the presence of the lilling yarn 30. The lling detector fork tines 3 I, 32 and.33 are rigidly Yaffixed .to block 3.4 .which in .turnfispivotally mounted, by .means of l.pin.35, .slot.'l'bftheffilling fork lslide l2. .Attachedto .the block '34 .at. approximately right angles to the Vtines `3 I, .32. and .33 .is .a .loop `member .36.adapted .to engagea notchf3'ljl in,goose` neck I1. Theloop l'36 beingfree to pivotby virtue of ,pivot pin 35 .normally rests on projectionsf extending from .the inner sides of slot. I6.

.Conventional means, not illustrated, are also .provided for moving the goose neck yI1 longitudinally in-s`lot IB toward ,block v3.4 .on alternate picks when ,theshuttle .is on thatside-of `the lay adjacent .the lling .detecting device. .As the lay approaches full beat-up position then-lines 3.I, .32 .and A.3.3 contact thelling yarn .3.5land are pivoted about pivot pin 35therebyraising loop 36 so v.that it fails .to Yengage vnotch 31 lin goose neck I'I .when the gooseneck is .otherwisein proper ,position .for engagement` vOn .the .other hand if thereis no filling yarn-present, the .tines 3I,.32.and.33 enter openings24, 25 and 2.6 in grate I9, .so .that .the lling '.detectorfork .29 is not Apivoted and .loop .3.6 engages notch v31 in.go0se When thegoose neck.I1 moves .toward the ...front of the ,loom,it thereby, by .virtue of .its A engagement with .loop .3.6, slides the lling fork .slide I2 .forward which stops .the .operation @of ftheloom. .The operator. can .then determine for what .reason 1 there is no .lling yarn present.

From the .above description of ..the.operation .of ,the 'filling yarn detector it canbeseen that if for any.reason..the tines .3I, 32 and 33 Aare prevented .fromentering openings .24,-25 and.26 in ,grate I9, the yarn detector will-fail tooperate even ...though 4there is no llingyarn in .front of grate I9. In priorart. apparatusitwas found .that lint .sooncollectedonlbarsi211, 2I,.22 vand 23 .of grate I9 to -suchanextent thatcit preventedtines..3l, 32 and 33 .from .entering .openings 24, .25. and 2,6 .eventhoughtheHing yarn 30 was not present, andin such .instances .the'loom. continued. to op- .erate until the absence .of the .llingyarn was .visually noticedby the operator. By .virtueof ,the ,improvement of `this. invention, .thegrate I 9 fails .to collect suflicientlintto. give. a false test for. the iilling yarn .and .the trouble Vpreviously .encountered for. this. reason. is eliminated.

.I claim:

:1. In,l aflilling .detecting device ,for aloomsaid device comprising a grate and .a pivoting fork having a number of tines designed to cooperate with said grate by pressing a filling yarn against the face of the grate, the fork thereby being pvoted to indicate the presence of said llng yarn, and by passing said tine through the openings of said grate when no filling yarn is present,

the fork thereby not being pvoted to indicate the absence of a lling yarn, the improvement which comprises a grate having external surfaces composed of a synthetic polymeric material selected from the group consisting of polytetrauoroethylene and polytriuorochloroethylene.

2. The improvement of claim 1 wherein the grate comprises a metal body having a surface coating of polytetrauoroethylene.

3. The improvement of claim 1 wherein the grate is molded of polytetrauoroethylene.

4. The improvement of claim 1 wherein the grate comprises a metal form with a surface coating of polytriluorochloroethylene.

5. The improvement of claim 1 wherein the 10 grate is molded of polytrfiuoroohloroethylene.

ROBERT M. INGHAM, JR.

No references cited. 

